linux-kernel - Re: [PATCH 4/8] usb: typec: mux: Find the muxes by also matching against the device node

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Message-ID: <CAHp75Vc8cwsrErkDvXptUE40AqpOiJt-U48UdRmKcsW3dZPkOA@mail.gmail.com>
Date:   Mon, 28 Jan 2019 18:17:24 +0200
From:   Andy Shevchenko <andy.shevchenko@...il.com>
To:     Heikki Krogerus <heikki.krogerus@...ux.intel.com>
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Chen Yu <chenyu56@...wei.com>, Jun Li <jun.li@....com>,
        Hans de Goede <hdegoede@...hat.com>,
        USB <linux-usb@...r.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 4/8] usb: typec: mux: Find the muxes by also matching
 against the device node

On Mon, Jan 28, 2019 at 5:46 PM Heikki Krogerus
<heikki.krogerus@...ux.intel.com> wrote:
> On Mon, Jan 28, 2019 at 11:53:54AM +0200, Andy Shevchenko wrote:
> > On Fri, Jan 25, 2019 at 3:17 PM Heikki Krogerus
> > <heikki.krogerus@...ux.intel.com> wrote:

> > > +       bool match = !con->id;
> >
> > I don't see how this assignment is used.
>
> That definitely deserves a comment at least.
>
> This series adds support for the "device graph" to the device
> connection API, but it is also possible to describe connections with
> normal references (fwnode_property_get_reference_args()). With normal
> references we don't need to do any extra identification like we do
> with device graph.
>
> The idea is to supply the connection id only if it has not been
> "consumed" already (device graph case). If it has been "consumed", we
> know there is no need for any extra connection identification (normal
> references), and we can jump straight to the next stage -> find the
> mux..
>

> > > +       if (!con->fwnode) {
> > > +               list_for_each_entry(mux, &mux_list, entry)
> > > +                       if (!strcmp(con->endpoint[ep], dev_name(mux->dev)))
> > > +                               return mux;
> > > +               return ERR_PTR(-EPROBE_DEFER);
> > > +       }
> > > +
> > > +       if (match)
> > > +               goto find_mux;
>
> ..here.
>
> I'll change this so that the match variable is introduced without
> setting default value. Instead, how about this:
>
>         /*
>          * Check has the identifier already been "consumed". If it
>          * has, no need to do any extra connection identification.
>          */
>         match = !con->id;
>         if (match)
>                 goto find_mux;

Cool, thanks!


-- 
With Best Regards,
Andy Shevchenko